CN111837847A - Ningxia rice shallow sowing and water feeding cultivation method - Google Patents

Abstract

The invention discloses a method for cultivating Ningxia rice in water after shallow sowing, which comprises the steps of land preparation, fertilizer operation, seed selection, seed treatment, sowing, weeding, pest control, water layer management, reseeding, seedling supplementing, harvesting and the like. The invention aims at special climatic conditions in Ningxia regions, follows the growth rule of rice, and scientifically manages different growth stages of the rice, thereby achieving the purposes of reducing cost, improving efficiency and improving the yield and quality of the rice. The whole process is simple, the operation is convenient, the planting cost is low, and the method has obvious economic and social benefits for agricultural development and farmer income increase.

Description

Ningxia rice shallow sowing and water feeding cultivation method

Technical Field

The invention belongs to the technical field of rice planting, and particularly relates to a method for cultivating Ningxia rice in water after shallow sowing.

Background

Rice is a cereal crop of the genus Oryza, native to China and India, and has been grown seven thousand years ago by the precedents of the Yangtze river basin of China. The rice planting is an important part of Chinese agricultural production, large-area planting is carried out in the middle and south of China, and the rice is always a main source of food in China. The planting of the rice is a complex and delicate process, the planting of the rice comprises the sowing of the rice, the nursing of the rice in the growing period and the harvesting of the rice, and the sowing method of the rice comprises a direct sowing type and a transplanting type, wherein the direct sowing type comprises a seed sowing type and a bud scattering type, and the transplanting type comprises a seedling throwing type and a seedling transplanting type. Among all the sowing methods of rice, the seedling transplanting type is the most complicated and difficult sowing method, but the seedling transplanting type can be carried out in paddy fields with deep water, and other modes cannot have the flood fighting capability; the seedling throwing type seedling throwing machine also has certain shallow water resistance, but the seedling throwing breeding process is very complicated, and the seedlings which are just thrown can be washed away and damaged by rain and water flow; the most rapid method is a seed sowing method, namely, seeds are directly sown in a field, but the sown seeds are affected by bird damage and decayed teeth, so that the germination rate is low.

At present, rice is one of the important grain crops in China and plays an important role in national economy. With the increase of population, the reduction of cultivated land, the shortage of water resources, the threat of drought, the promotion of returning to cultivation and the like, a series of problems objectively aggravate the contradiction of food demand, and the problems of laggard rice planting method and lower yield in China cause various hidden dangers and risks in the current food problems in China. The rice is a marked crop which is reputed by 'Shangjiang south' in Ningxia yellow irrigation areas, is also a crop with better benefit in Ningxia main grain crops, and has strong regional advantages and industrial development advantages. The development of direct seeding cultivation mode has important significance for promoting the updating and updating pace of rice varieties in our district, realizing continuous grain yield increase and increasing income of farmers.

The rice breeding needs to change around market demands, takes the sexual safety as a core, takes the green development as a lead, takes the quality improvement as a direction, and promotes the structural reform and the green development of the agricultural supply side in our area on the basis of guaranteeing the grain safety. Ningxia belongs to a dry single cropping rice crop belt in northwest China, the natural conditions of the whole northwest single cropping rice crop belt have the threats of low temperature, cold damage and frost in the early stage and the mature stage, and the yield and quality of rice are severely restricted by the conventional rice planting method, so that the rice planting method aiming at the climatic conditions of Ningxia areas has great significance.

Disclosure of Invention

The invention aims to provide a water-feeding cultivation method of rice after shallow sowing in Ningxia region. Aiming at Ningxia climate conditions, the invention realizes the yield and quality increase of rice by strict management standards of the planting process in water.

In order to achieve the technical purpose, the invention is specifically realized by the following technical scheme:

a method for cultivating Ningxia rice in water after shallow sowing comprises the following steps:

1) soil preparation

And (3) after harvesting the previous stubbles, deeply ploughing and cleaning stubbles, leveling the field in the middle 3 th day to the beginning 4 months, and re-raking the field by using a gap harrow to sun the soil after finishing the field leveling.

In the middle ten days of 4 months, after mechanical fertilizing, the soil is loosened and loosened in large and wide corners, the field is flat and bumpy, the seed is prevented from drilling into the soil joint to affect the seedling protection, and the ridge is formed after the land is ploughed.

2) Fertilizer operation research

Applying inorganic fertilizer per mu in the whole growth period: 17.5kg of pure nitrogen (N) and phosphorus pentoxide (P)₂O₅)9kg of potassium oxide (K)₂O)3kg, wherein: the nitrogen fertilizer is basal applied by 40 percent, the dressing is carried out by 60 percent, and the phosphorus and potassium fertilizer is all basal applied.

Organic fertilizer: 30-50kg of organic fertilizer or 500-1000kg of decomposed farmyard manure is applied to each mu of land by combining with a heavy harrow.

3) Seed selection

Selecting variety Fuyuan No. 4, Ningjing No. 41, Ningjing No. 45, Ningjing No. 49, etc.

4) Seed treatment

After sun-planting in late 4 months, the rice seeds are coated with a coating agent.

5) Seeding

Sowing after the local average temperature is stable at 10 ℃, spraying 200ml of butralin or high-efficiency prosulfocarb or 15kg of water per mu after sowing, and sealing the field.

6) Weeding

Chemical weed killing is carried out when the leaf age reaches 3-3.5 leaves and the seedling height is 9-11 cm.

7) Water layer management

After the rice is sowed, performing primary irrigation, wherein the water layer is 12-15 cm; then, carrying out dry-wet alternative irrigation before the 3-leaf stage of the rice seedlings, so as to be beneficial to rooting and seedling emergence; maintaining the water layer at the tillering stage for 3-6 cm; water is cut off and the field is baked during the jointing and booting period; after the rice is aligned with the ears, the rice is transferred into a dry-wet alternative water layer for management.

8) Reseeding

Reserving 2-3kg of rice seeds in each field during initial irrigation, soaking the seeds at the same period for accelerating germination, and timely replanting the rice seeds at the mouth of the water inlet field or the position where the ridge is flushed down after the initial irrigation is finished; in the 5-6 leaf stage of rice, the blank point, ridge edge and ground edge in the rice field are manually replanted in time to preserve the seedlings.

9) Harvesting

And (4) leveling the ridge in the middle and last ten days of 9 months, and harvesting when the rice grains of more than 98% of rice ears on the field surface reach the middle and later stage of waxiness and 95% of the rice grains turn golden yellow from the last ten days of 9 months to the last ten days of 10 months.

Further, the land leveling is to level the mouth of the land, cut the straight edge of the land, level the furrow, the height difference of the unit irrigation surface is 2-3 cm.

Further, the heavy harrowing and drying soil is to harrow the soil with the depth of 15-18cm, harrow the four sides and the ground corners thoroughly, avoid harrowing, cut the ground straight and create a deep soil layer to improve the ground temperature.

Furthermore, 40% of nitrogen fertilizer is basal applied, 60% of additional application is carried out, and all phosphorus and potassium fertilizers are basal applied.

Further, harrowing is carried out for the last time, the fertilizer applied by the base is mixed uniformly, and the mixture is uniformly sown into the soil by adopting a mechanical fertilizer sowing method.

Further, sun-drying seeds specifically comprises the steps of spreading seeds on a clean and flat cement ground in sunny days and sun-drying the seeds for 1-2 days, wherein the spreading thickness of the seeds is controlled to be 2-3cm during sun-drying.

The invention has the beneficial effects that:

by following the growth rule of rice, scientific management is carried out on different stages of the growth of the rice, the rice field is water-saving, drought-resistant and soil permeability is improved, accurate fertilization and pest control are carried out on the field, and the aims of reducing cost, improving efficiency and improving yield and quality are achieved. The whole process is simple, the operation is convenient, the planting cost is low, and the method has obvious economic benefit and social benefit for agricultural development and farmer income increase.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to specific embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Description of the terms in the present invention:

1. water-feeding cultivation technique after shallow sowing of rice

The method is a simplified and light rice cultivation mode, wherein the sowing depth is controlled within 1cm of the ground surface, and a water layer is established after the drought is closed.

2. Tianzui

The water filling siltation layer is arranged in the radius of 5-10m of the water inlet.

3. Initial irrigation

First irrigation is carried out after rice seeding.

4. Seedling stage

The rice has the period of 4-6 roots and 5-10cm long.

5. Drying by falling

The water layer on the surface of the field is naturally evaporated and seeped, and most of the surface of the field is kept without water accumulation.

6. Water-expansion mud-expansion management

And (3) irrigating water from a small part of exposed water layer to a large part of exposed water layer on the field surface, and draining water until the small part of exposed water layer is exposed on the field surface after irrigation until no water layer is exposed on the field surface.

7. Airing field

Irrigation is not performed in time after the water falls to dryness, and the surface of the field is kept moist without accumulated water. And (4) airing until the surface of the field is cracked, and irrigating and establishing a water layer when the ground surface at a high position is whitish.

8. Roast field

In order to control the excessive growth of rice, the water is cut off for a long time until the surface of the field is cracked and the color of the leaves of the rice seedlings is changed from dark green to light green.

The invention provides a method for cultivating Ningxia rice in water after shallow sowing, which comprises the following steps:

1. soil preparation method

1.1 deep ploughing stubble cleaning

And deeply ploughing and cleaning stubbles after harvesting the previous stubbles, wherein the ploughing depth is 20-25cm.

1.2 Pan

In the middle 3 th month, directly discharging into rice field by using a traction earth-hanging plate, then leveling the land block by using a laser land leveling machine, leveling the mouth of the land, cutting the land edge, leveling the ridge ditch, and making the height difference of the unit irrigation surface be 2-3 cm.

1.3 heavy harrowing and drying soil

And (3) from late 3 months to early 4 months, raking the field again by using a gap rake after the field flattening is finished, drying the soil, wherein the rake depth is 15-18cm, the rake is raked completely through four edges and ground corners, the rake is not leaked, and the ground is cut straight to create a deep soil layer so as to improve the ground temperature.

In the middle ten 4 months, after mechanical fertilizer spreading, a rotary cultivator or 41 disc rakes are used for raking the soil diagonally, so that the base fertilizer is uniformly mixed into the soil, and the full-layer fertilizer spreading is realized. After harrowing, the seeds are used in a large and square place with opposite angles, the field surface is flat and bumpy, and the influence of the penetration of the seeds into the soil seams on the seedling protection is prevented. The land surface before watering should reach the quality standard of' land level, soil breaking, and both the upper and lower extreme.

1.4 ridging

Ridging after the land is built, wherein the width of the bottom of the ridging is 80-90cm, the width of the top of the ridging is 25-30cm, and the height of the ridging is 32-38 cm; the two ends are tightly connected, and the height, the width and the width are consistent. And (4) leveling ridge ditches mechanically or manually, and additionally spreading fertilizers on two sides of the ridge before watering.

2. Fertilizer operation research

2.1 scientific fertilization

700 kg yield, inorganic fertilizer is applied per mu in the whole growth period: 17.5kg of pure nitrogen (N) and phosphorus pentoxide (P)₂O₅)9kg of potassium oxide (K)₂O)3 kg; wherein: the nitrogen fertilizer is basal applied by 40 percent, the dressing is 60 percent, and the phosphorus and potassium fertilizer is all basal applied. Organic fertilizer: in the fields with relatively poor geographical conditions, 30-50kg of organic fertilizer or 500-1000kg of decomposed farmyard manure (sheep manure, cattle manure, pig manure and the like) is applied in combination with ploughing (or heavily raking and harrowing) per mu.

The fertilizer application scheme comprises the following steps: 1. 15kg of diammonium phosphate, 10kg of urea, 6kg of potassium sulfate and topdressing urea: 8kg of seedling fertilizer, 10kg of tiller fertilizer and 2 kg of spike fertilizer urea; 2. And (3) converting the amount of the special fertilizer for basal application rice according to the dosage of nitrogen, phosphorus and potassium, and applying urea: 8kg of seedling fertilizer, 10kg of tiller fertilizer and 2 kg of spike fertilizer urea.

2.2 manure for transport stable

Before the autumn deep ploughing or after the spring open field is finished, various animal manure (pig manure, sheep manure, cattle manure and the like) is delivered into the field in time, and are uniformly piled and covered with 1-3cm soil layers to promote maturity and prevent sun and wind erosion.

2.3 broadcast application of miscellaneous fertilizers

Before the farm is raked and aired, the rotten animal manure piles in the field are manually beaten into blocks, impurities are picked up and uniformly scattered, and the farm is raked into the soil conveniently.

2.4 applying base fertilizer

And combining the final harrowing, uniformly mixing all the fertilizers applied to the base, and uniformly sowing the mixed fertilizers into the soil by adopting a mechanical fertilizer sowing method. The fertilizer should be applied to the field side with accurate mu quantity and no leakage.

2.5 dressing fertilizer for seedlings

25-30 days after the rice is watered, when the leaf age of the rice is 3-3.5 leaves, the endosperm nutrient medium is basically exhausted in the period, the root system is underdeveloped, the fertilizer absorption capacity is weak, topdressing is carried out in time, strong seedlings are cultivated, chemical weeding death seedlings are reduced, and the seedling protection rate is improved. In this period, 20 percent of pure nitrogen in the whole growth period is applied per mu, namely 4kg, which is equivalent to 8kg of urea.

2.6 tiller fertilizer

Tillering is started at the 3.5-4 leaf age stage of the rice, the vegetative growth speed is accelerated, and topdressing is performed in time to promote tillering and tillering to form ears. In this period, 27% of pure nitrogen in the whole growth period, namely 4.6kg, is applied per mu, which is equivalent to 10kg of urea. During top dressing, the rice seedlings should float properly according to the growth vigor, top dressing is carried out on the principle that more seedlings are planted with less strong seedlings and more weak seedlings (the leaves are yellow), and the principle that urea does not exceed 10kg is mastered to prevent fertilizer damage. During topdressing, a water layer of 4-6cm is established on the field surface to avoid topdressing with dew to prevent seedling burning.

2.7 spike fertilizer

And in the 7-leaf period (inverted 2-leaf period), the rice enters the vigorous jointing stage (the total leaf number is different due to the difference of variety characteristics and the growth period of the variety, the leaf number of the variety suitable for dry and shallow sowing in the Ningxia irrigated area is generally 10-12 leaves in the full growth period, 3-5 joints of an extension joint are provided, 60 percent of basal parts are extended by 0.5-1cm, the differentiation of young ears is started, the vegetative growth and reproductive growth are combined, nutrients are supplemented timely, the development of rice ears is promoted, and large ears are formed.

2.8 granular fertilizer

In the full heading period of the rice, 1.5kg of pure nitrogen is additionally applied to fields or part of rice in the fields which are weak in growth vigor and yellow in leaf color and show lack of fertilizer and are fertilized or are in the fields, and 2-3kg of urea is converted, so that the development of grains is promoted, and the thousand kernel weight is increased. The additional fertilization should be done with caution, and if the rice leaves are dark and growing well, no or little additional fertilization should be done, otherwise, the number of the additional fertilization should be increased.

2.9 foliar fertilizer

At different growth periods of rice, leaf surface additional fertilizer is carried out by combining pest control to supplement trace elements, so as to improve the growth vigor of seedlings, prevent fertilizer loss and increase thousand-grain weight. The concentration of the foliar fertilizer should be controlled at 0.5-2%.

3. Seed preparation

3.1 variety selection

The variety selection is carried out according to the characteristics of water feeding cultivation after shallow sowing of rice, and the selection of the water feeding cultivation after shallow sowing is carried out by paying attention to the following three aspects:

firstly, in the mature period, the variety is preferably selected to ensure safe maturity, namely a medium-mature variety, and the growing period is about 145 days, and the number of the varieties is 1 less than that of the rice seedlings.

The second is a variety which is suitable for close planting, has moderate tillering power, small reduction of grain number per ear under the condition of close planting, short plant, upright leaf blade, good light-receiving situation, strong lodging resistance, wide disease resistance and strong disease resistance.

Thirdly, selecting a variety with good low-temperature germination, strong seedling growth vigor, strong ear-stage cold resistance and good seedling and growth under the flooding condition.

At present, the main high-quality varieties suitable for water cultivation after shallow sowing in Ningxia irrigation areas include rich source No. 4, Ningjing No. 41, Ningjing No. 45, Ningjing No. 49 and the like.

3.2 seed treatment

3.2.1 seed drying

And in the last ten days of 4 months, spreading the seeds on a clean and flat cement ground for sunning for 1-2 days in sunny days, controlling the spreading thickness of the seeds to be 2-3cm during sunning, and tedding the seeds once every 1-2 hours by using a wood spade to ensure that the dryness is consistent. So as to reduce the water content of the seeds and the breakage of the seeds and improve the activity and the germination potential of the seed enzyme.

3.2.2 Disinfection

In late 4 months, the sun-dried rice seeds are coated with a coating agent such as 'Liangdun' + 'Shaisheng' or 'Daozuole' and the like, so as to kill germs on the surface of the rice hulls and latent between the seed coats of the rice and prevent bakanae disease and rice blast.

4. Seeding

4.1 sowing time

Sowing can be carried out after the local average temperature is stable and passes 10 ℃. The seed sowing progress is combined with the water regime and the rotation irrigation system to determine the specific time. The sowing depth is controlled within 1cm of the surface, and the soil is pressed after sowing.

4.2 sowing quantity

The seeding quantity is determined according to tillering capacity, soil fertility level, seed quality and the like of different varieties. The seed amount per mu is about 20 kilograms.

5. Weeding

5.1 seal after sowing

After the rice is sowed, spraying 200ml kilograms of butralin or high-efficiency prosulfocarb or 15kg of water per mu, and sealing the field. The dosage is accurate, the spraying is even, no leakage occurs, and the initial irrigation is immediately carried out.

5.2 chemical weeding at full-term

Chemical weed killing is carried out when the leaf age reaches 3-3.5 leaves and the seedling height is 9-11 cm. The herbicide should be selected according to the weed species in the rice field. The weeds in the rice field mainly comprise three types, namely grassy weeds (mainly barnyard grass), broad-leaved weeds and cyperaceae weeds, if the grass-leaved weeds in the rice field are mainly barnyard grass, herbicides mainly comprising barnyard grass and secondarily comprising broad-leaved weeds and cyperaceae weeds are selected for weed control, 40-60ml of Daojie (2.5% penoxsulam) and 20kg of water are sprayed for weed control per mu, accumulated water in the rice field is drained before spraying, two thirds of the weeds are exposed out of the water surface, a water layer is built for 5-7cm in 24-48 hours after spraying, and the water layer is kept for 5-7 days.

5.3 Artificial auxiliary weed control

Weeds missed to be killed in the field are removed in time on the basis of chemical weed control. When artificial weeding is carried out, the root connection is pulled out, and the later-stage regeneration is prevented.

6. Water layer management

6.1 initial irrigation

After the rice is sowed and irrigated, the irrigation progress and the rotation irrigation system are combined to advance canal by canal and section by section, water is replenished while primary irrigation is carried out, and the water layer is required to reach 12-15 cm. When in initial irrigation, slow water enters the field and small water is irrigated slowly to soak the soil and reduce the area of the water inlet nozzle. The initial irrigation is based on the early irrigation of late-maturing varieties and the late-maturing and early-maturing varieties, and is finished 5 months and 5 days before, and the dry condition is ensured to fall 10 days before 5 months.

6.2 Water layer management during the seedling stage

The water layer management in the seedling protection period should carefully carry out the key technical key fields of 'soaking seeds in heavy water, drying for accelerating germination and dry, wet and rolling away'. Firstly, a stable water layer (with the depth of 12-15cm) is established on the field surface after the initial irrigation, so that the seeds absorb water and swell as soon as possible, the function of alkali pressure washing salt is exerted, and good field conditions are created for rice seed germination and root pricking; and fifthly, during the period of falling, drying and airing, water supplement is carried out alternately in a dry-wet mode and seedlings are exposed by covering water layers, so that the growth of the root system is promoted, the purposes of protecting the whole seedlings and strengthening the seedlings are achieved, and the phenomena of large water seal, seedling lifting and weak growth and development of the root system of the rice seedlings, dead seedlings and floating seedlings are avoided.

6.3 Water layer management at tillering stage

In the last 6 months, the rice leaves breast at the three-leaf stage, is put into autotrophy and then enters the tillering stage, and the management center is to promote the tillering to grow early and quickly and to grow strong tillering. Shallow water management (3-6cm) should be adhered to increase the ground temperature and promote the growth of leaf buds. Most varieties planted in Ningxia regions are 14-leaf varieties, tillering can basically form ears, in general, the 4 th leaf grows out, the 1 st leaf starts to tillering, tillering of 4-6 leaves can form ears, tillering is effective or ineffective, tillering of 4 leaves can form ears in the jointing stage, otherwise, tillering is ineffective; when the total stem number in the field reaches 60-80 ten thousand seedlings, tillering control is adopted. This period ends in the middle and late 6 th of the month.

6.4 Water layer management at the ear-stage of jointing and pregnancy

In late 6 months, after 8-9 leaves of the rice enter an ineffective tillering stage, the rice begins to pull out the nodes and bear the ears, the rice is cut off water and roasted when the population target reaches about 80 percent of the ears, when the total stem number reaches 70-80 ten thousand plants, a water layer (8-12cm) is properly enlarged in the 7-8 leaves stage to inhibit ineffective tillering, the field with over-vigorous growth is roasted, the growth and development of the main stems and the effective tillers are promoted, the field is roasted according to the standard, the soil surface has cracks and does not sink feet, the morphological leaves of the rice plants become yellow, the field with growth deviation is irrigated with intermittent shallow water, tillering fertilizer is applied for promoting 6 kilograms, and tillering and forming the ears are promoted. From the late stage of rice ear bearing to before ear picking, the growth period of overground part is the most vigorous period, the vigorous period of physiological water demand is the peak period of the growth and development of root system of rice in one life. Not only needs enough irrigation quantity to satisfy the growth of rice plants, but also satisfies the growth of root systems by soil ventilation. Adopting a shallow-wet alternative irrigation method, irrigating a water layer with the same depth after 2-3cm water naturally falls to dry (3-5 days), and repeating the steps to form a shallow-water layer and wet-wet alternative irrigation mode; if the temperature is lower than 15 ℃ at night, the water layer (12-15cm) is properly enlarged to prevent low-temperature cold damage and glume flower degeneration and promote big ears and more grains.

6.5 Water layer management during heading, flowering, and grouting periods

In the key period from 8 middle ten days to the last ten days of the month, the rice is transferred to a dry-wet alternative water layer for management after being aligned with ears, namely, the later water is not in the front water (the field surface is cracked, the high part is whitened), the permeability of plough layer soil is improved, the activity of root systems is prolonged, the purposes of root cultivation and leaf preservation, premature senility prevention, green area enhancement or prolonging, rice plant photosynthesis function improvement and root system activity improvement are achieved, and the purpose of increasing thousand seed weight is achieved. In this period, the establishment of a large water layer for a long time or the absence of water in the field surface for a long time is avoided, so as to prevent lodging and influence on rice grouting. Most of the rice ears in the field are lowered, water is cut off when most of the rice grains reach the middle stage of maturity, a water outlet is dug at the low-lying position to drain the area of the field and prevent rainfall and water accumulation, so that lodging is prevented and mechanical harvesting is influenced. The early-maturing variety is water cut off at the bottom of 8 months, and the late-maturing variety is water cut off at the beginning of 9 months.

And (3) mastering the principle of irrigation: in the initial irrigation period, seeds are soaked in large water, and a white twisting nozzle precipitation layer is exposed for heat preservation (water is not added, so that the water adding times are reduced); shallow water intermittent irrigation at the tillering stage cannot be carried out, and deep water can not be filled, so that tillering is promoted; combining large water tillering control and drainage field baking in an ineffective tillering stage, controlling ineffective tillering and reducing nutrient loss; the wet irrigation is carried out in the stage of topping and booting, deep water cannot be kept, a water layer of heavy water (15 cm) is irrigated when the temperature is lower than 15 ℃ at night after 10-15 days of heading, cold damage is prevented, low-temperature weather is avoided, heavy water is not irrigated, intermittent irrigation is carried out, excessive growth of internodes is prevented, and later-stage lodging is prevented. And (3) performing dry-wet alternative irrigation in the heading-grouting period.

Leaf age mode calculation method: elongation internode number ═ main stem total leaf number ÷ 3, as: the total number of leaves is 12, the number of elongation internodes is 4, and the number of elongation internodes of 14 leaves is 5; the effective tillering temporary leaf age period is the total leaf number of main stems-the number of elongated internodes, the total leaf number is 12, the effective tillering temporary period is 7-8, the total leaf number is 14, and the effective tillering temporary period is 8-9; the leaf-turning age in the node-pulling stage is 2 of the number of elongated internodes, 12 leaves in the total number of leaves, 10 nodes in the total number of leaves, 14 leaves in the total number of leaves and 11-12 nodes in the total number of leaves.

Leaf age observation method: painting the blades in the 4-leaf stage, painting the blades in the 7-leaf stage and painting the blades in the 10-leaf stage, and growing the blades for about 5 days.

6.6 quantitative index of the change of the leaf color of the population

The rice leaf growth has 4 change rules, namely the leaf color at the tillering stage is black, the color of the uppermost leaf is darker than that of the adjacent lower leaf, if the opposite is true, the management or fertilization measures are not in place, the leaf color at the tillering stage is gradually faded, and the color of the uppermost leaf is consistent with that of the adjacent lower leaf; the color of the leaf at the ineffective tillering stage and the jointing stage is obviously yellow, and the color of the top leaf is lighter than that of the adjacent lower leaf; in the jointing stage, 15-20 days after heading, the color of the leaf should be changed to black obviously, and the color of the top leaf should be consistent with that of the adjacent lower leaf. The leaf color turns yellow after heading for 15-20 days, and the green-blue late maturity is prevented and controlled, so that the yield and the quality are influenced.

7. Replanting seeds and seedlings

7.1 reseeding

Reserving 2-3kg of rice seeds in each field during initial irrigation, soaking the seeds at the same period for accelerating germination, and timely replanting the rice seeds at the mouth of the water inlet field or the place where the ridge is flushed down after the initial irrigation is finished.

7.2 transplanting of seedlings

In the 5-6 leaf stage of rice, the blank points, ridges and ground edges in the rice field are manually replanting and seedling is preserved. During seedling transplanting, the ridges are heightened and reinforced, the ridge ditches are filled up, and then the seedling transplanting is carried out to enlarge the effective area and increase the yield of rice, and the seedling transplanting of the variety with weak tillering is finished before 6 months and 25 days.

8. Pest control

8.1 weeding and pupa removing

And (4) shoveling and burning all weeds in the ditches and the ditches completely to eliminate cordyceps sinensis and bacteria sources from 12 months to 2 months.

8.2 chemical control

The diseases and insect pests of paddy rice in irrigation areas mainly comprise rice blast, leaf spot of flax, bakanae disease, banded sclerotial blight, striped rice borer, rice planthopper and rice clump leaf roller; the prevention and control of diseases and insects should be based on the principle of prevention and comprehensive control. In the last 7 th month, because the number of leaves and tillers in the rice field is increased, the field is shaded and is poor in ventilation and light transmission, diseases and pests such as rice blast, leaf spot of flax, rice planthopper and the like begin to occur, and the medicines are required to be taken according to the disease conditions. For the first time of treating fungal diseases and insect pests such as rice blast, 80-100g of 20% "tricyclazole" or 100ml of "Fuji No. 1" plus 30ml of cyhalothrin (pyrethroid insecticide for colleges and universities) can be added with 20kg of water for spray control. The method is mainly used for preventing and treating rainy and high-humidity meteorological conditions and fields with large field density. The disease-preventing drugs should be used alternately. The spraying should be uniform, no leakage, accurate dosage, and ensure control effect. The general prevention is carried out for 2 times in the whole growth period, the first time is in the last 7 months, and the second time is after the heading. The prevention and treatment of bakanae disease mainly includes seed disinfection. Insect pest control should select different types of insecticides according to the type and harm characteristics of the insect pest.

9. Harvesting

9.1 Ridge laying

In the middle and last ten days of 9 months, the ridges of the field are placed flat, the ridges are arc-shaped after the flat placement, the ridges are 10-15cm high, and the ridges can smoothly pass through the ridges when the field is harvested mechanically so as to prevent the quality of harvesting and plowing from being influenced.

9.2 Harvest stage

From last ten days of 9 months to last ten days of 10 months, when more than 98% of the rice grains on the field surface reach the middle and later stage of the wax ripeness, 95% of the grains turn golden yellow, and the period when the branches and stalks of the rice ears turn yellow is the optimal harvesting period. Harvesting in time is achieved during harvesting, and the timely harvesting is an effective method and measure for improving the quality of rice. The harvest period is too early, so that threshing is not clean, and the field loss rate and the green grain rate are increased; when the harvesting period is too late, the paddy is exposed and solarized at night, so that the waist explosion rate is increased; thereby reducing the quality of the product and influencing the quality of the rice.

9.3 harvesting machine

When harvesting, the rice is harvested in sections according to different varieties and different maturity conditions so as to reduce the waist-cracking rate of the rice, improve the rate of the whole polished rice and improve the commodity quality and quality of the rice. A semi-feeding combine harvester and a full-feeding combine harvester with better performance are selected as much as possible in the harvesting machine, and the machine which has harvested different varieties is thoroughly cleaned before harvesting, so that the machine is prevented from being mixed.

10. Sunning ground management

After the rice is harvested and enters the field, the rice harvested in the early stage is aired in time, and the rice of different varieties is harvested and aired separately to prevent the rice from being mixed. When the water content of the rice reaches 14-15%, winnowing is carried out, empty and shriveled grains, rice knots and other impurities are removed through air separation, and the impurity rate of the rice after air separation is less than 2%. And when the water content of the paddy is less than 13.5%, bagging, warehousing and selling. During storage, the warehouse or shed is kept dry, and attention should be paid to prevent contamination, worm damage, mildew, and damage of sparrows.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (6)

1. A method for cultivating Ningxia rice in water after shallow sowing is characterized by comprising the following steps:

1) soil preparation

And (3) after harvesting the previous stubbles, deeply ploughing and cleaning stubbles, leveling the field in the middle 3 th day to the beginning 4 months, and re-raking the field by using a gap harrow to sun the soil after finishing the field leveling.

In the middle ten days of 4 months, after mechanical fertilization, the soil is loosened and tilled with large and generous angles, the field is flat and bumpy, the seed is prevented from drilling into the soil joint to affect the seedling protection, and the ridge is formed after land preparation.

2) Fertilizer operation research

Applying inorganic fertilizer per mu in the whole growth period: 17.5kg of pure nitrogen (N) and phosphorus pentoxide (P)₂O₅)9kg of potassium oxide (K)₂O)3kg, wherein: the nitrogen fertilizer is basal applied by 40 percent, the dressing is carried out by 60 percent, and the phosphorus and potassium fertilizer is all basal applied.

Organic fertilizer: 30-50kg of organic fertilizer or 500-1000kg of decomposed farmyard manure is applied to each mu of land by combining with a heavy harrow.

3) Seed selection

Selecting variety Fuyuan No. 4, Ningjing No. 41, Ningjing No. 45, Ningjing No. 49, etc.

4) Seed treatment

After sun-planting in late 4 months, the rice seeds are coated with a coating agent.

5) Seeding

Sowing after the local average temperature is stable at 10 ℃, spraying 200ml of butralin or high-efficiency prosulfocarb or 15kg of water per mu after sowing, and sealing the field.

6) Weeding

Chemical weed killing is carried out when the leaf age reaches 3-3.5 leaves and the seedling height is 9-11 cm.

7) Water layer management

After the rice is sowed, performing primary irrigation, wherein the water layer is 12-15 cm; then carrying out dry-wet alternate irrigation, and keeping wet irrigation after 3 leaf periods of the rice seedlings; maintaining the water layer at the tillering stage for 3-6 cm; water is cut off and the field is baked during the jointing and booting period; after the rice is aligned with the ears, the rice is transferred into a dry-wet alternative water layer for management.

8) Reseeding

Reserving 2-3kg of rice seeds in each field during initial irrigation, soaking the seeds at the same period for accelerating germination, and timely replanting the rice seeds at the mouth of the water inlet field or the position where the ridge is flushed down after the initial irrigation is finished; in the 5-6 leaf stage of rice, the blank point, ridge edge and ground edge in the rice field are manually replanting and seedling is preserved.

9) Harvesting

And (4) leveling ridges in the middle and last ten days of 9 months, and harvesting when more than 98% of rice grains on the field surface reach the middle and later stage of waxiness and 95% of grains turn golden yellow from the last ten days of 9 months to the last ten days of 10 months.

2. The method for cultivating Ningxia rice in water after shallow sowing as claimed in claim 1, wherein the land leveling includes leveling the mouth, cutting the land edge, leveling the ridge and furrow, and setting the height difference of the irrigation surface to 2-3 cm.

3. The method for cultivating Ningxia rice in water after shallow sowing as claimed in claim 1, wherein the deep harrowing is carried out for 15-18cm deep, the harrowing is carried out through four sides and corners of the land, the harrowing is carried out without leakage, and the land is cut straight to create a deep soil layer to raise the ground temperature.

4. The method for cultivating Ningxia rice in water after shallow sowing as claimed in claim 1, wherein nitrogen fertilizer is applied in 40% and supplementary fertilizer is applied in 60% and phosphate-potash fertilizer is applied in all basal.

5. The method for cultivating Ningxia rice in water after shallow sowing as claimed in claim 1, wherein the final raking step includes mixing the fertilizer with the base fertilizer and applying the mixture to soil via mechanical fertilizer application.

6. The method for cultivating Ningxia rice in water after shallow sowing according to claim 1, wherein the sun-seeding is to spread the seeds on a clean and flat cement ground for 1-2 days in sunny days, and the spreading thickness of the seeds should be controlled to be 2-3cm during sun-seeding.